CHANGELOG update.

Author: rhysrevans3

CHANGELOG.md

@@ -12,6 +12,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ### Changed
 
+- Changed assets serialization to prevent mapping explosion while allowing asset inforamtion to be indexed. [#341](https://github.com/stac-utils/stac-fastapi-elasticsearch-opensearch/pull/341)
+
 ### Fixed
 
 ## [v6.2.1] - 2025-09-02